Komatsu issued this shop manual as WEBM003900, and its 286 pages are the factory service book for the PC35R-8 and PC45R-8 hydraulic excavators. That OEM number matters: it marks the genuine Komatsu PC35R-8, PC45R-8 shop manual PDF, not a retyped summary. Hydraulic schematics trace flow from the pump through the control valve and pilot circuit, while wiring diagrams follow the harness from battery to starter and alternator. Testing and adjusting procedures take you through engine speed and hydraulic drift checks, and the maintenance standard section sets wear limits for the swing circle, final drive, sprocket, idler, and track rollers. Warm the oil to 45-55°C (113-131°F) before any drift test, then torque the PC35R-8 final drive screws to 120 Nm on reassembly. A drifting boom is a guess without the spec. Keyword-search the bookmarked PDF, find your number, and put the machine back on the cut.
What's Inside This Komatsu PC35R-8, PC45R-8 Manual
| System | Pages | Key Topics |
|---|---|---|
| Structure and Function | 21-102 | Power Train, Swing Machinery, Hydraulic Pump, Control Valve |
| Testing and Adjusting | 103-162 | Engine Speed, Hydraulic Drifts |
| Removal and Installation | 163-248 | Starter Motor, Alternator, Injection Pump, Nozzle Holder, Water Coolant Pump, Cylinder Head, Radiator Group |
| Maintenance Standard | 249-286 | Swing Circle, Swing Machinery, Final Drive, Sprocket, Idler, Track Roller |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Standard tightening torque for 16mm bolt | 191 ± 21 Nm | p. 12 |
| Hydraulic oil temperature for test conditions | 45-55°C (113-131°F) | p. 120 |
| Check valve spring free length x O.D. | 30.1 x 15.7 mm | p. 270 |
| Check valve spring installed length | 15.7 mm | p. 267 |
| Main Relief Valve Pressure | 245 bar | p. 53 |
| Swing Circle Bolt Torque | 130 Nm | p. 250 |
| PC35R-8 | ||
| Sprocket wheel screws torque | 120 Nm (88.4 lb.ft.) | p. 214 |
| Working equipment weight | 320 kg | p. 237 |
| Bucket weight | 68 kg | p. 238 |
| Travel Motor High Speed (PC35R-8) | 16.00 cm3/rev | p. 77 |
| Travel Motor Low Speed (PC35R-8) | 26.30 cm3/rev | p. 77 |
| PC35R | ||
| Clearance between shaft and bushing | 0.144 - 0.196 mm (0.0057 - 0.0077 in.) | p. 259 |
Komatsu PC35R-8, PC45R-8 Common Problems This Manual Covers
Komatsu PC35R-8 loses hydraulic power once oil warms up, boom and arm slow to a crawl
Check main relief pressure with hydraulic oil warmed to 45-55°C (113-131°F), the test condition on page 120. Compare your reading against the 245 bar (3568 psi) spec on page 53. If pressure falls off only when hot, suspect internal pump leakage or a worn relief seat; adjust the relief valve first, then flow test the pump.
Manual Section: Pressure Regulation in Hydraulic Circuits p. 53One track travels weak or machine veers to one side on flat ground
Verify which side carries the fault by swapping the travel lines between motors at the control valve; if the weak side moves with the hoses, the problem is in the valve or pilot circuit, not the travel motor. Run the comparison with oil at 45-55°C (113-131°F), page 120, then drain the final drive and check the oil for metal.
Manual Section: Testing and Adjusting p. 120Swing motor whines and upper structure drifts or will not hold on a slope
Drain the swing motor case and check the oil for metal flake. Measure piston to cylinder bore clearance against the 0.01-0.02 mm standard and shoe to piston clearance against 0.03-0.15 mm on page 270; replace the rotating group when wear passes those figures. While you are in there, torque swing circle bolts to 130 Nm with Loctite 262, page 250.
Manual Section: Maintenance Standard p. 270Lower track rollers leaking oil, squealing, and track runs rough over the frame
Inspect each lower roller with the track jacked clear; spin it by hand and reject any roller that grinds or weeps oil at the seals. Replace worn rollers in sets so the chain runs flat, and torque 16 mm undercarriage mounting bolts to 191 ± 21 Nm using the chart on page 12.
Manual Section: Maintenance Standard p. 259Bucket pins and bushings worn loose, bucket rattles and cuts uneven grade
Measure bucket dimension A against the 85 mm (3.349 in) standard on page 238 and replace pins and bushings once wear passes the 83.5 mm (3.290 in) service limit. Fit new pins clean and dry, grease them immediately, and recheck play after the first shift; loose pins hammer the bores oval fast.
Manual Section: Maintenance Standard p. 238Frequently Asked Questions
What is the standard torque specification for the track roller bolts on the PC35R-8 and PC45R-8?
The standard torque for the track roller bolts is 190 Nm (140 lb.ft.) for the PC35R-8 and 270 Nm (199 lb.ft.) for the PC45R-8, using Loctite 262. p. 222
What is the standard valve clearance for the intake and exhaust valves on the Komatsu PC35R-8, PC45R-8 engine?
The standard valve clearance for both intake and exhaust valves when the engine is cold is 0.20 mm (0.008 in.). p. 128
What is the standard fuel injection timing for the engine?
The standard fuel injection timing for the engine is 14 ± 1 degrees before top dead center (BTDC). p. 104
What is the capacity of the hydraulic oil tank for the PC35R-8 and PC45R-8?
The hydraulic oil tank capacity for the PC35R-8 is 63 liters (16.6 US gal) for the first filling and 33 liters (8.7 US gal) for a change. For the PC45R-8, the capacity is the same. p. 17
What is the standard tightening torque for the cylinder head screws on a Komatsu PC35R-8, PC45R-8?
The cylinder head screws should be tightened to a torque of 88.2 ± 2.94 Nm (65 ± 2.2 lb.ft.). p. 178
How will I receive this Komatsu PC35R-8 Shop Manual?
One searchable PDF covering 286 pages, delivered instantly. No disc, no shipping, no waiting on the post.
Can I print a copy of this Komatsu PC35R-8 Shop Manual for the shop?
Yes. The PDF is DRM-free, so printing works from any reader and any printer.
Reviews
There are no reviews yet.